Hey Gotte, just had a random thought. With all the paranoia surrounding luggage on airplanes these days, I figured I'd tell you what we ended up doing at the London airport to be able to "pass" our bike boxes as safe luggage.
Don't seal your bike box before you get to the airport. Most bike boxes will fit through the oversized luggage x-ray, but there's a chance that they won't. Some security guards might also want to take an extra good look at the box contents despite what the x-ray says. Basically what we did is keep the side flap of the box open so the security could have access to the contents if they so wished. We requested that they perform a thorough check, and then attach a sticker to the box saying that it had been safety-inspected. Then we closed the box and sealed it (with the miles of clear tape that we'd brought with us) in their presence. We also had the official flyer describing the purpose and function of our camp stove, in case that caused concern (stranger things have happened). Of course we had to come to the airport earlier to do all of this, but that's better than having our boxes confiscated altogether!
*sigh* I wonder if all this paranoia will ever die down, or if travel by air is only going to get more and more and more oppressive...